Crisis of Leadership is a term used by Trotskyists to describe the fundamental problem holding back the working class from political power in the epoch of imperialism.
Trotsky argued that only Stalinists, centrists and reformists who hold the leadership of the class and its vanguard hold back the working class from political power when capitalism has reached the point that it is ready for socialism.
This is shown in a quote from Trotsky's The Death Agony of Capitalism and the Tasks of the Fourth International (1938): "All talk to the effect that historical conditions have not yet 'ripened' for socialism is the product of ignorance or conscious deception.
Without a socialist revolution, in the next historical period at that, a catastrophe threatens the whole culture of mankind.
The importance of this today is the different positions held by Trotskyist groups on this question - indicating their views on programme and epoch.